sheet3

sheet3/345/benchmark.cpp

@@ -0,0 +1,127 @@
+#include <iostream>
+#include <vector>   
+#include <cmath>
+using namespace std;
+
+
+// Inner product
+double benchmark_A(const vector<double> &x, const vector<double> &y)
+{
+    double sum = 0.0;
+     for (unsigned int i = 0; i < x.size(); i++)
+    {
+        sum += x[i]*y[i];
+    }
+    return sum;
+}
+
+//Matrix-vector product
+vector<double> benchmark_B(const vector<double> &A, const vector<double> &x)
+{
+    unsigned int N = x.size();
+    unsigned int M = A.size() / N;
+    vector<double> b(M, 0.0);
+
+    for (unsigned int i = 0; i < M; i++)
+    {
+        double bi = 0.0;
+        for (unsigned int j = 0; j < N; j++)
+        {
+            bi += A[i*N+j]*x[j];
+        }
+        b[i] = bi;
+    }
+
+    return b;
+}
+
+
+//Matrix-Matrix product
+vector<double> benchmark_C(const vector<double> &A, const vector<double> &B, unsigned int M)
+{
+    unsigned int L = A.size()/M;
+    unsigned int N = B.size()/L;
+    vector<double> C(M*N,0.0);
+     for (unsigned int i = 0; i < M; i++)
+    {
+        for (unsigned int j = 0; j < N; j++)
+        {
+            double sum = 0.0;
+            for (unsigned int k = 0; k < L; k++)
+            {
+                sum += A[i*L+k]*B[k*N+j];
+            }
+            C[i*N+j] = sum;
+        }
+    }
+
+    return C;
+
+}
+
+//polynomial evaluation
+vector<double> benchmark_D(const vector<double>& coeff, const vector<double>& x)
+{
+    unsigned int p  = coeff.size();   // p coefficients, degree p-1
+    unsigned int N  = x.size();
+    vector<double> y(N);
+
+    for (unsigned int i = 0; i < N; i++){
+        double yi = coeff[p-1];
+        double xi = x[i];
+        for(int j=p-2; j>=0; --j)
+        {
+            yi = yi*xi+coeff[j];
+        }
+        y[i] = yi;
+    }
+    return y;
+}
+
+//TASK 5
+double norm2(const vector<double>& x)
+{
+    double s = 0.0;
+    for (unsigned int i = 0; i < x.size(); ++i)
+        s += x[i]*x[i];
+    return sqrt(s);
+}
+
+double scalar_kahan(const vector<double>& x, const vector<double>& y)
+{
+    double sum = 0.0;
+    double c   = 0.0;   
+
+    for (unsigned int i = 0; i < x.size(); i++)
+    {
+        double prod = x[i]*y[i];
+        double yk = prod - c;
+        double t  = sum+yk;
+        c= (t - sum) - yk;
+        sum = t;
+    }
+    return sum;
+}
+
+//Matrix-Matrix product
+vector<double> matrixMultColumnWise(const vector<double> &A, const vector<double> &B, unsigned int M)
+{
+    unsigned int L = A.size()/M;
+    unsigned int N = B.size()/L;
+    vector<double> C(M*N,0.0);
+     for (unsigned int i = 0; i < M; i++)
+    {
+        for (unsigned int j = 0; j < N; j++)
+        {
+            double sum = 0.0;
+            for (unsigned int k = 0; k < L; k++)
+            {
+                sum += A[k*L+i]*B[k*N+j];
+            }
+            C[i*N+j] = sum;
+        }
+    }
+
+    return C;
+
+}